There are consequences of the Holocaust that remain unsolved. We can think, for example, of the claims for the restitution of the properties that were seized by the Nazis, especially art pieces that still have not been resolved. The absence of competent international organs to resolve these cases, along with the scarce international norms that are effectively applicable to events happening before their entry into force, brings us to a diverse scene marked by the heterogeneity of national legislations and national courts rulings. On the other side, American courts have ruled several times on these matters, systematically leaving aside the exception of expropriation. These decisions arise compatibility issues with the existing set of international norms –which has nowadays a customary nature– about the immunity of the States and their properties, as well as with the most recent case law of the International Court of Justice on this issue